New Xenon headlamps are optional, which produce the low beam by a 35 Watt Xenon bulb. The Xenon bulbs produce three times the light of the conventional H7 bulb while using less electricity.
The Xenon headlamp assembly consists of the following components:
- Headlamp housing
- Headlamp housing cover
- Xenon bulb for low beam 12 V 35 W
- Halogen bulb for high beam and headlamp flash H7 - 12 V 55 W
- Turn signal bulb 12 V 21 W
- Parking lamp bulb 12 V 5 W
- Headlamp levelling motor
- Starter module
- Control module
Function
WARNING:Voltages of up to 30 kV are possible.
Like sunlight, the light produced has very high levels of green and blue fraction.
The special design of the bezel and the diffuser produce a significantly increased range and a much broader short range spread. This allows better illumination of the side of the road without exceeding the statutory limits for causing dazzle.
Another advantage of the chosen light distribution is softening of the light and dark boundary. Excessive contrast between the light and dark zones could cause disturbing changes in the road surface illumination when the vehicle is moving. In all, the Xenon headlamps produce a significant improvement in active safety.
With Xenon headlamps the full brightness is only achieved after a few minutes of switching on. Therefore, usage in motor vehicles require special electronics to ensure full brightness in the first second.
The arc chamber of the Xenon bulb is filled with Xenon and a mixture of metal halide salts.
A high voltage of 20 kV surge ignites the arc between the two electrodes. After a brief excess current phase in which the arc stabilizes, the lamp output is regulated to 35 watts by the electronics.
The bulb wear is so low that the Xenon bulb lasts the life of the vehicle.
The front parking lamps and turn signal lamps are integrated into the headlamp housing and cannot be removed separately.
Conventional Headlamps
The front parking lamps and turn signal lamps are integrated into the headlamp housing and cannot be removed separately. The headlamp is fitted with a H7 bulb for the low beam and a H1 bulb for the high beam and the headlamp flash.
Headlamp Levelling System – Xenon Headlamps
A headlamp washer system and an automatic headlamp levelling system is required for vehicles with Xenon headlamps to comply with national legislation.
The system consists of the following components:
- Vehicle level sensors on the front and rear axles
- Master control module on the left-hand headlamp housing
- Slave control module on the right-hand headlamp housing
- Headlamp levelling motors in both headlamp housings
The system automatically adjusts to the laden state of the vehicle when the ignition is switched on to avoid dazzling oncoming traffic.
No adjustment of the range take place during the dynamic processes (braking, accelerating, initial drive).
NOTE:After removing the left headlamp assembly (master), a headlamp level sensor or disconnecting of the electrical circuit, a new calibration of the headlamp levelling system is required and must be initialized with WDS.
A vehicle level sensor on the front and rear axle sends the master control module a voltage signal according to the suspension compression. This master control module calculates the optimum inclination of the headlamps according to the difference between the two signals and sends the required position to the slave control module. Both modules generate the control signal for the headlamp levelling motors in comparison of the present reflector position to the required reflector position.
When the low beam is switched on, the system compares actual conditions with original adjustment. This prevents a reduction in road surface illumination and avoids dazzling of oncoming traffic.
Headlamp Levelling System – Conventional Headlamps
NOTE:Basic adjustment of the headlamps must always be carried out with the headlamp levelling system set to position "0”.
Each headlamp unit incorporates a levelling motor, which is activated electrically and controlled by the switch. The motor moves the pivoting reflector by means of an adjustment spindle until it reaches the required setting.
The headlamp levelling control switch has two stops. The switch clicks in place in position "0”, which corresponds to the basic setting. The headlamps are inclined downwards at their maximum angle when the switch is set to position "4”.
The headlamp levelling system is operated by means of voltage controlled DC motors. A potentiometer inside the headlamp levelling switch is used to adjust a voltage (required value). Following the same principle, the actuator in the motor produces a voltage that depends on the position of the adjustment spindle (actual value).
The electronics built into these systems compares the required value (setting of the switch) with the actual value (adjustment spindle setting). Depending on the voltage difference the reflectors are swivelled up or down until the two voltages are the same.
In case of a signal failure the system adjusts to a safety position (low beam) to comply with national legislation.
Headlamp Washer System
A headlamp washer system is required for vehicles with Xenon headlamps to comply with national legislation. This takes the form of a high-pressure washer system.
When inactive, the telescopic nozzle holder is concealed in the bumper.
As soon as the windshield washer system is operated with the headlamps switched on, the telescopic nozzle holder extends and cleans the external surface of the headlamp (plastic cover) with a high-pressure jet of water.
An additional high-pressure pump is mounted on the washer fluid reservoir for the high-pressure washer system.
